Fire fighting aircraft



Dec. 2, 1969 1 T. w'ARD FIRE FIGHTING AIRCRAFT Filed NOV. 15, 1967INVENTOR LEO T. WARD 14 11.03: & 140-016 United States Patent Office3,481,405 Patented Dec. 2, 1969 3,481,405 FIRE FIGHTING AIRCRAFT Leo T.Ward, 1450 4th Ave., San Diego, Calif. 92104 Filed Nov. 13, 1967, Ser.No. 682,119 Int. Cl. A62c 1/14, 13/24, 3/00 US. Cl. 169-1 6 ClaimsABSTRACT OF THE DISCLOSURE An aircraft capable of very low speed flight,such as a helicopter, is adapted to carry a gas generator whlch producesa high velocity jet flow of non-combustible gas, the apparatus includingmeans for directing the jet to a fire to extinguish the fire and blowaway or erode oombustlble surface material in the fire zone. The jet isexpelled equally in opposite directions from the aircraft, so that thereis no reactive force applied to deflect the aircraft from its line offlight.

BACKGROUND OF THE INVENTION nel to enter the treated area and completethe job, usually by clearing a fire break to stop the advancing flames.The process is very time consuming and dangerous SUMMARY OF THEINVENTION The apparatus described herein can be incorporated intovarious conventional helicopters or can be constructed as a completeassembly to be suspended from a helicopter. One or more. gas generators,such as conventional turbojet engines, are mounted so that the exhaustis directed to the side of the helicopter, equally in oppositedirectionsto avoid any offset thrust reaction. This can be accomplishedby identical opposed engines, or a split nozzle on one engine. Controlmeans is provided to incline the jet nozzle downwardly on one side todirect the exhaust gases at a fire on the ground below and to the sideof the helicopter, which is flown along the fire front. The gases canalso be deflected through a limited angle from front to rear tofacilitate sweeping an area of fire while the helicopter hovers or movesvery slowly. Jet engine exhaust gases lose their heat very rapidly and,at a short distance from the nozzle are sufliciently cool to avoid anypossiiblity of initiating combustion, particularly since a jet engine isquite efiicient in combustion and the gases are essentiallynon-combustible. The jet velocity, however, is very high for aconsiderable distance. from the nozzle, being sufficient for the presentpurpose at as much as 50 or 100 feet, depending on the size of engineused. In addition to blowing out the flames in the immediate area anddistributing non-combustible gases over the surrounding area, the forceof the jet exhaust is suflicient to blow loose debris back into thefire. and even to erode the surface and uproot grass and light brush.This, in effect, creates a fire break simultaneously with subduing theflames and requires very little added work by ground 7 BRIEF DESCRIPTIONOF THE DRAWING FIGURE 1 is a front elevation view of a typicalhelicopter with the fire fighting apparatus installed and showing theoperation;

FIGURE 2 is a side elevation view of the helicopter;

FIGURE 3 is an enlarged sectional view taken on line 3-3 of FIGURE 2;

FIGURE 4 is a sectional view taken on line 4-4 of FIGURE 3;

FIGURE 5 is a side elevation view of a fire fighting unit for attachmentbelow a helicopter; and

FIGURE 6 is a sectional view taken on line 66 of FIGURE 5.

Similar characters of reference indicate similar or identical elementsand portions throughout the specification and throughout the views ofthe drawing.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the configuration shown inFIGURES 1-4, the apparatus is installed inside a conventional cabin typehelicopter 10 and includes a gas generator 12 having an air inlet 14well clear of the exhaust gas zone. The gas generator may be aconventional type of turbojet engine and is mounted in the helicopter inany suitable manner, the longitudinal arrangement shown being used tosimplify the nozzle structure.

At the rear of gas generator 12 is a bifurcated nozzle 16 having a pairof opposed outlets 18 and 20 which project through openings 22 in thesides of the helicopter. Nozzle 16 has a sleeve portion 24 which iscoaxially coupled to the tail pipe 26 of the gas generator by a ringbearing 28, so that rotation of the nozzle will direct the outlets up ordown from the helicopter. To rotate the nozzle 16, a gear sector 30 issecured on the portion of ring bearing 28 carried by the nozzle, and apinion 32, coupled to any suitable manual or power operated controlmeans, engages the gear sector. Other means for rotating the nozzle maybe equally suitable.

Across each outlet of nozzle 16 are vanes 34 pivotally mounted betweenbrackets 36 to swing about axes substantially perpendicular to therotational axis of the nozzle. All of the vanes at each outlet areconnected by links 38 to swing in unison, and the two sets of vanes areinterconnected by an actuating rod 40 which is coupled to a bell crank42 pivotally mounted on a bracket 44 on sleeve. portion 24. Frombell-crank 42 a control rod 46 extends to any suitable control means.When control rod 46 is moved, one set of vanes 34 will swing in aforward direction and the other set will swing in the opposite, or aftdirection.

In operation the helicopter is flown at low altitude along the edge of afire and nozzle 16 is rotated to direct the exhaust from gas generator12 down to the burning area to be extinguished. Due to the bifurcatednozzle, an equal flow of gas is ejected in the opposite direction, socancelling any offset thrust on the helicopter and making itsimpler tofly where needed. This equal and opposite reaction is maintainedregardless of the position of the nozzle. The blast of the jet exhaustwill blow the flames back and the non-combustible gases will subduecombustion. In addition, loose combustible material will be blown backinto the fire and grass and small brush will be loosened and blown backas the jet exhaust erodes the surface of the ground. Thus a fire breakis made as the fire is being extinguished along its edge. The helicoptercan be maneuvered as necessary to follow the fire and, where necessary,the vanes 34 can be used to sweep the jet exhaust back and forth acrossa selected area. Such a pro- 0 cedure greatly reduces the need for aground crew and,

when personnel are used in the area, the presence of the helicopter is asafety factor.

It will be obvious that any reasonable number of gas generators may beused, either coupled to a single bifurcated nozzle, or with individualnozzles, as long as the gas flow is equally opposed to prevent offsetthrust.

A multiple unit suitable for use on large helicopters is shown inFIGURES 5 and 6. This unit 48 is self-contained and can be suspendedfrom a helicopter or attached as a pod to a helicopter of the flyingcrane type, indicated in a broken line at 50 in FIGURE 5. A frame 52 ofany suitable structure has a rocking platform 54 pivotally mounted atthe lower end thereof to swing about a longitudinal axis relative to theaircraft. An arm 56 on hinge shaft 58 is conncted to a jack 60 mountedon the frame 52, to adjust the inclination of platform 54 to eitherside. On top of the platform 54 is a rotary platform 62 mounted on aturnatble 64 and driven by a motor 66. Any conventional means may beused to move the platforms, that shown being substantially diagrammatic.

Mounted on platform 62 are paired gas generators 68 and 70, two pairsbeing shown as an example, all the gas generators having inlets 72directed to avoid ingestion of combustion gases. Each pair of gasgenerators 68 and 70 has outlets 74 and 76, respectively, opening inopposite lateral directions for balanced thrust. Sweeping of the jetexhaust from front to rear is accomplished by rotating platform 62, asindicated in broken line in FIG- URE 6. In the open frame unit this ismore practical than multiple sets of interconnected vanes, and the gasgenerators can be balanced about the axis of rotation to minimize loads.

By making successive passes, or using several helicopters in series, itwould be possible to subdue a fire and make a fire break along aconsiderable frontage of a fire in a short time. With suitable fuelsupply a helicopter could opearte for some time continuously and sustainits fire fighting action in a particular area, as opposed to thechemical or water dropping operations which require frequent round tripsfor refilling.

It is understood that minor variation from the form of the inventiondisclosed herein may be made without departure from the spirit and scopeof the invention, and that the specification and drawing are to beconsidered as merely illustrative rather than limiting.

What is claimed is:

1. In combination with an aircraft capable of very slow and hoveringflight, fire fighting apparatus comprising:

gas generator means for generating a high velocity flow of substantiallynon-combustible gases;

said gas generator means being mounted on the aircraft and having atleast one pair of equal flow outlets in fixed, axially opposed relationto each other and opening to opposite sides of the aircraft for balancedthrust; and

. I 4 directing means coupled to said outlets to direct selectiv elyaagular'tyuawnwardt 'dfi theirre's'pective sides of the aircraft.

2. The structure of claim 1, and including means for directing the gasflow from said outlets angularly from front to rear relative to theaircraft and in opposed directions on opposite sides of the aircraft.

3. The structure of claim 1, wherein said outlets are at opposite endsof a bifurcated nozzle coupled to said gas generator means and mountedto rotate about an axis substantially parallel to the longitudinal axisof the aircraft, with the outlets protruding from opposite sides of theaircraft.

4. The structure of claim 3, and including vanes across each of saidoutlets, pivotally mounted to swing about axes substantiallyperpendicular to the rotation axis of said nozzle; and

actuating means interconnecting said vanes at the opposed outlets toswing the vanes in opposite directions.

5. The structure of claim 1, and including a rocking platform on whichsaid gas generator means is mounted, said platform being pivotallyattached to. the aircraft on an axis substantially parallel to thelongitudinal axis of the aircraft;

said directing means comprising actuating means for inclining saidplatform to either side.

6. The structure of claim 5, and including a rotatable platform mountedon said rocking platform for rotation about an axis substantiallyperpendicular to the pivotal axis of the rocking platform, said gasgenerator means being mounted on said rotatable platform; and

means to rotatesaid rotatable platform through a limited angular rangeto swing said outlets from front to rear.

References Cited UNITED STATES PATENTS 3,136,488 6/1964 Petlak et al. z239-129 XR 3,209,535 10/1965 Marchant et al. 24452 XR 3,220,482 11/1965Eveleth 244136 XR 3,273,651 9/1966 Andrews 1691 3,280,560 10/1966Marchant et al. 244-52 XR 3,290,885 12/1966 Thomas 24452 XR MILTONBUCHLER, Primary Examiner P. E. SAUBERER, Assistant Examiner U.S. Cl.X..R. 159 2; 239 171, 129, 565,552, 590.5; 244' 17.11

